Synthesis and Reactions of Triptycene‐Derived Bromocalix[5]arenes: Conformational Transformation from Cone to 1,2‐Alternate

Triptycene‐derived p ‐dibromocalix[5]arene was synthesized by a fragment‐coupling approach, whereas treatment of the triptycene‐derived calix[5]arene containing three p ‐ tert ‐butyl phenol groups and a 1,8‐dimethoxytriptycene moiety with excess bromine in dichloromethane at room temperature produced triptycene‐derived p ‐pentabromocalix[5]arene directly. Methyl etherification and Suzuki coupling reactions were then carried out. As a result, a series of triptycene‐derived calix[5]arene derivatives in fixed cone and 1,2‐alternate conformations were obtained. Moreover, conformation transformations of triptycene‐derived calix[5]arenes from cone to 1,2‐alternate forms could also be achieved.